The invention relates to a device for producing different hole patterns in sheet-shaped print materials.
In the printing industry, there is a need to punch print materials, especially in preparation for a binding process, by means of which individually printed sheets can be combined into a brochure or a ring-bound book using a wire comb or plastic binding, or as an alternative method for storing the sheet-shaped print materials, for example, in binders or document covers.
Of the numerous devices and methods known from the prior art for punching holes in sheet-shaped print materials, one group makes up those devices and processes that carry out on-the-fly processing of sheet-shaped print materials. The term on-the-fly processing is understood to mean that the sheet-shaped print materials are processed while moving, in contrast to systems in which several sheet-shaped print materials are punched or cut while stationary. In on-the-fly processing, the sheet-shaped print materials are typically processed individually and then collected, while in other processes the sheet-shaped print materials are first collected and then processed. On-the-fly processing of sheet-shaped print materials has the advantage that this processing better corresponds to the work sequence of a printing machine for sheet-shaped print materials that typically prints the sheet-shaped print materials sequentially. Therefore, on-the-fly processing is suitable for further print processing, especially for in-line devices, as they are called, that are connected directly to a printing machine such as this, for example, a digital printer or copy machine. On-the-fly processing is, however, not tied to in-line devices, rather it can also be advantageously used in off-line devices that are not directly connected with a printing machine.
The hole patterns that are put into sheet-shaped print materials basically differ in the position and number of holes that are punched. This means that a difference is made, for example, between the European 2- or 4-hole pattern or the US 2, 3, 4, 5 or 7-hole pattern.
It is advantageous to design a punching device that is as flexible as possible since the requirements, for example, on the position of the holes or their number, can vary from one printing and/or further processing job to the next. U.S. Pat. No. 2,116,391 discloses a device for flexible adjustment of punching patterns in a punching device. In this case, individual punches are fastened to ring gears that can be moved axially. Because of the ring gears that are additionally equipped with a scale, a precise angular positioning of the punches on the circumference of the ring gear is achieved; the same is true for the positioning of the associated female dies. In the solution named in the document above, the punches are bolted individually in their planned position. Consequently, a flexible change is in fact possible but involves considerable time.
U.S. Pat. No. 5,669,277 suggests a rotary hole-punching device, in which brackets are provided in a first shaft for punches for a number of different hole combinations. Changing between different hole patterns requires putting in or taking out the associated punch from the corresponding bracket. This allows for attaining a high precision of the punch positions. On the other hand, the disadvantage is that the punches have to be changed manually for each change in the punching pattern.
The published German patent application (OLS) DE 34 27 686 A1 discloses a device in which a number of punches are mounted radially on a punching ring of a hole-punching device at specific distances from each other such that the punches can be moved radially by means of internal cam rings between a first outer punching position and a retracted passive position. In addition, the punching rings can be slid on the shaft along the axis so that a large number of different punching patterns can be created. The disadvantage of the solution described is that it is not possible to change the punching patterns while the operation is in progress.
International application WO 98/55278 suggests a method for changing perforation patterns, in which perforation tools are also brought radially out of a passive position and into an active position and thus result in a change in the perforation pattern. For this purpose, the perforation tools are resiliently supported against a hose, whereby the hose winds in a helical or double-helical form around the roller and within the roller holding the tools. Inflating the hose causes the tools to be raised into their active position. The advantage of this design is that it is possible to change between the punch patterns here at any time. On the other hand, the disadvantage is the limited number of different punching patterns that depend on the number of hoses that wind around the roller holding the tools since it is always an entire hose that is inflated.
The published German patent application (OLS) DE 28 11 109 discloses a modular design of a transverse perforation device in which the perforation processes are distributed, i.e., carried out by separate rollers and whereby the spacing of the lateral perforation is controlled by changing the relative position of the rollers with respect to one another. Depending on the number of separate perforation rollers, different perforation patterns can be achieved in this way. The disadvantage here is that a large number of movable parts are necessary.
European patent application EP 1029640 A2 discloses a lateral processing device that has two processing units arranged in succession and thereby represent two successive processing levels, whereby one of the processing units can be selected respectively by using a control. In one embodiment, the lateral processing device is made up of a first synchronous cutter and a directly adjacent dynamic variable cross cutter. According to the disclosure, one of the lateral cutters respectively can be stopped so long as the other one is working. The individual cutter that is stopped in this case forms an opening into which a guide table can be introduced. The optional use of two cross cutters allows for cutting a greater number of different formats. Also, it is suggested there that the same principle can be used, instead of cross cutting, for punching different hole patterns.
When making a series of perforations along one side of a sheet-shaped print material for a ring binding, e.g., wire comb or plastic binding, it is advantageous if the holes are made in the sheet-shaped print material in such a way that the edges of the sheet-shaped print material running perpendicular to these are not damaged. Therefore, it is desirable to provide a punching device with which this is possible and with which the greatest possible available number of different hole patterns can be punched in sheet-shaped print materials and a change between the different hole patterns can be implemented quickly.